Custom Event Bus

Build your own EventBus implementation for any message transport — Redis Streams, Pub/Sub, NSQ, anything.

Implement the EventBus interface to integrate any transport that isn't covered by the shipped adapters.

You can implement the EventBus interface directly for any message transport. If your bus needs an async connection step, also implement Connectable — the Domain will auto-call connect() during wiring:

adapters/redis-event-bus.ts

import type {
  EventBus,
  AsyncEventHandler,
  Connectable,
  Event,
} from "@noddde/core";

export class RedisEventBus implements EventBus, Connectable {
  private readonly handlers = new Map<string, AsyncEventHandler[]>();

  async connect(): Promise<void> {
    // Connect to Redis
  }

  on(eventName: string, handler: AsyncEventHandler): void {
    const existing = this.handlers.get(eventName) ?? [];
    this.handlers.set(eventName, [...existing, handler]);
  }

  async dispatch<TEvent extends Event>(event: TEvent): Promise<void> {
    // Publish to Redis Streams, Pub/Sub, etc.
  }

  async close(): Promise<void> {
    this.handlers.clear();
    // Disconnect from Redis
  }
}

The requirements are:

dispatch() publishes to all subscribers for the event name.
on() supports multiple handlers per event name (fan-out).
close() releases all resources and is idempotent.
connect() (if implementing Connectable) establishes the connection and is idempotent.